Senior Full-Stack Engineer — Subscriptions & IAP (6-Month Contract)

Proximity Works; United States; Remote; USD 150,000 - 190,000; Part time

Job summary

Proximity Works is seeking a strong Full Stack Engineer to join our Subscriptions and Payments engineering team. You will build and scale consumer-facing systems across web, mobile, and connected-TV platforms, with emphasis on performance and reliability during high-traffic events.

You will design and implement scalable Java/Spring Boot services, modern frontend using React/TypeScript, and REST/microservices for subscription workflows, while collaborating with cross-functional teams.

Qualifications

• 7+ years of software engineering experience.
• Strong system-design and architecture experience.
• Experience designing systems for high concurrency, large-scale traffic and high availability.
• Ability to drive complex technical implementations end-to-end.
• Experience mentoring engineers and influencing engineering best practices.

Responsibilities

• Design, develop and maintain scalable full-stack applications using Java and modern web technologies.
• Build frontend and backend capabilities supporting subscriptions, payments and entitlement management.
• Develop responsive, performant user experiences using JavaScript/TypeScript and React or similar frameworks.
• Build and integrate REST APIs and microservices for subscription and payment workflows.
• Work on Fire TV IAP integration, including purchases, renewals, cancellations and entitlement synchronization.
• Integrate with external payment providers, app stores and platform APIs.
• Build resilient systems capable of handling large traffic spikes and high concurrent usage.
• Improve application performance, availability, monitoring and reliability.
• Handle failure scenarios, retries, reconciliation and user-state consistency across distributed systems.
• Collaborate with backend, frontend, product and platform teams to deliver features end-to-end.
• Write high-quality, maintainable and well-tested production code.
• Participate in design reviews, code reviews and architecture discussions.
• Strong experience with Java, Spring Boot and RESTful services.
• Strong frontend experience with JavaScript/TypeScript, HTML and CSS.
• Experience with React, Next.js or similar modern frontend frameworks.
• Strong understanding of microservices and distributed systems.
• Experience building high-scale consumer-facing applications.
• Experience with SQL/NoSQL databases.
• Exposure to caching systems such as Redis.
• Experience with messaging/event-streaming technologies such as Kafka is preferred.
• Experience with cloud platforms such as AWS.
• Familiarity with Docker, Kubernetes and CI/CD.
• Good understanding of observability, monitoring and production debugging.

Skills

Java

Spring Boot

RESTful services

JavaScript/TypeScript

React

Next.js

Microservices

Distributed systems

SQL/NoSQL

Redis (Caching)

Kafka

CI/CD

Observability/Debugging

AWS

Docker

Kubernetes

Tools

Docker

Kubernetes

AWS

CI/CD tooling

Job description

Proximity Works is seeking a strong Full Stack Engineer to join our Subscriptions and Payments engineering team. You will build and scale consumer-facing systems across web, mobile, and connected-TV platforms, with emphasis on performance and reliability during high-traffic events.

You will design and implement scalable Java/Spring Boot services, modern frontend using React/TypeScript, and REST/microservices for subscription workflows, while collaborating with cross-functional teams.